Coil winding



W- C. GREF COIL WINDING Jan. 9, 1951 2 Sheets-Sheet 1 Filed March 24, 1948 FIG. 2

FIG. 3

INVENTOR Afar/v 60/75/222 62?) ATTORN EYS Jan. 9, 1951 w. c. GREF 2,537,457

con. WINDING Filed March 24, 1948 2 Sheets-Sheet 2 W W, mz, 7mm I ZWWW ATTO NEY Patented Jan. 9, 1951 0011. WINDING William Constant Gref, Westport, Conn, assignor to Starring & Company, Inc., Bridgeport, Conn, a corporation of Connecticut Application'March 24, 1948, Serial No. 16,751

20 Claims. 1

This invention relates to the winding of coils,

and; is especially adapted to winding coils of wire.

More specifically, the invention. comprises a method and meanswhereby thestarting end of the coil is automatically located and anchored within the hollow form or'tube on which the coil is wound, in sufficient length to. comprise an electrical connection lead. which. may readily be withdrawn from the tube."

Heretofore, coils of wire such as employed in electrical apparatus have been wound on coil winding machines which are largely automatic inoperation'. Examples of such coils include electromagnet coils, transformer coils and choke coils. These are customarily wound on a hollow form or winding tube of insulating material such ascardboard or heavy paper in concentric layers usually separated fromeach other by sheets of insulating material. The outside or finishing turn is readily anchored wherever it happens to be on the coil by a strip of insulating material, such as paper, secured to thecoil by adhesive so that the end. of the wire in sufficient length to comprise a connection lead extends from under such strip. However,the beginning or starting end of the coil must be anchored at exactly the'correct starting point on the winding tube to prevent crossed wires and short-circuited turns.- Usually this point is directly beneath a movable wire guide which is several inches above the winding tube. Therefore, to start the winding, the operator must first ascertain that thementioned' guide is in thestartingposition. She then draws the wire down to a point on the windingtube estimated to be directly below the guide, secures the starting end of the wire to the outside surface of the tube at that location by an adhesive anchor strip, and finally cuts off an wire which. extends from under the anchor strip. These manual operations, which must be repeated for the starting of each coil on the tube, are not only time-consuming but demand considerable skill on the part of the operator whose judgment thus determines the final spacing between adjacent coils.

Although, by the prior method just described, the inside or starting end of the wire will ordinarily be located near to one edge or end of the coil, it is nevertheless buried out of sight within the coil structure. Hence, the final steps in the manufacture of such coils have heretofore included the locating of this inside end of wire and releasing it with a suitable sharp tool by inserting the tool' between the outside surface of the winding tube and the first insulating sheet between the first and second layers of wire. After thisend'of 'wirehas'been located, about one turn of it is pulled out by hand so as to comprise the other electrical connection lead to the coil, after which this inside lead maybe suitably anchoredto prevent'more wire from being thereafter inadvertently drawn out.

Thus, both the starting and the finishing steps of manufacturing even an extremely simple form of electric coil have involved considerable hand labor with consequent time delay andat a cost which amounts to an appreciable proportion of the cost of the entire coil. Furthermore, the operation of fishing out the inside end of the wire frequently damages either i the insulation on the wire or the insulating sheets between the turns of wire, and sometimesbreaks the wire. The consequent scrapping of a large number of coils'thus rendered defective also constitutes a waste of materials and increases the net cost of manufacture.

The foregoing disadvantages heretofore experienced in the manufacture of coils areavoided by means of the present invention which introduces not only a saving of much time and labor, but also provides a more reliable and uniform product, as will be apparent from the following description of the invention considered in connection withthe drawings, wherein:

Fig. 1 represents a front view of part of a multiplecoil winding machine which includesthe present invention; 7

Fig.2 illustrates a winding arbor constructed in accordance, with the invention, as it would appear from the front of themachine of Fig. 1;

Fig. 3 shows a winding tube modified in accordance with the invention;

Fig. 4 is an end view of the elements shown in Fig. 2;

Fig. 5 illustrates the manner in which the starting end of the coil is automatically located on and secured to thewinding tube;

Fig. 6 illustrates the manner in which portions of the'starting end of the wires are drawn inside the winding. tube;' V

Fig. 7 isan enlarged cross-sectional View of the arbor, the winding tube and the starting end portion of'the coil, as taken along the line 'l--l of Fig. 6; and

Fig. 8 is a perspective view of'a completed coil wound in accordance with the invention.

Referrin now to Fig. l, certain parts of a coil winding machine fundamentally of well-known type are shown in their usual relation permitting the winding of four coils of wire simultaneously from four wires which are fed from a like number of spools, not shown. By way of example, the illustrated machine is shown as winding four similar coils simultaneously, although more or less coils could obviously be wound. Furthermore, the invention in its various aspects is not limited to the winding of metal wire, because it is equally well adapted to the winding of strands of materials. Hence the term wire as herein .employed should be interpreted accordingly.

The wire I, which may be assumed to comprise enameled copper magnet wire, is withdrawn from the spool on which it is customarily delivered and passes over sheaves 2 which are free both to rotate and slide on the supporting axle 3. Spaced from axle 3 so as to be in front of as well as below it, is a roller 4 suitably journalled in supports (not shown) so as to rotate with minimum friction. In the surface of this roller, guide grooves 5 are cut of a size just suflicient to receive the wire intended to be wound. These grooves are spaced apart on the roller the distance that the starting ends of the coils are to be spaced apart. If the spacing of the grooves, or the width or depth thereof is to be changed, it is customary to substitute a roller having grooves of the desired dimensions.

Below and slightly behind the front of roller 4, a winding arbor 6 is positioned, and is supported on both ends so as to be readily rotatable. The arbor is driven at speeds under the control of the operator, and may be started and stopped rapidly. Axle 3 and roller 4 are arranged to move together longitudinally under the automatic control of the machine so that as the arbor 6 rotates, the wire I will be automatically fed to the coils in the proper direction and at the correct rate of longitudinal movement, so as to wind coils of desired'length and of the required pitch. In ordinary coils this pitch is the same as the diameter of the wire, but it may be greater.

For various commercial and production reasons it has been customary to wind coils on a winding tube of heavy paper or the like having substantially square cross-section. Such tubes will fit snugly on an arbor having a square cross-section, especially if the corners of the arbor be rounded off slightly.

In accordance with the present invention, I have modified'the arbor and winding tube of the prior art so that they cooperate with each other in a new manner. Arbo 6 which, in Fig. 2, is shown broken off at the two ends because the manner of supporting and rotating it have not been illustrated, is constructed from square stock, as shown in Fig. 4. Along one corner of the arbor, a'spline 8 has been milled. The height of the spline in this instance is about one-fourth of the width of the arbor along its diagonal. T-shaped slots 9 are cut in the spline, as shown, at intervals determined by the length of the desired coils and the spacing :etween the coils. Hence this spacing will normally be the same as that between the grooves 5 on roller e. These slots form hook members it? which are flush with the surface of the arbor so as not to interfere with sliding the winding tube on and off the arbor. The winding tube does not slip around the arbor because both winding tube and arbor in the illustrated embodiment are square (Fig. '7). Slot 9 is of such depth and length as to receive the wire when it is caused to pass into the slot as will later be described.

Along one corner of tube 1 (Fig. 3) four slits! I are cut. These slits should be long enough to permit the wire, when drawn into them, to extend a suflicient distance into the inside of the winding tube to form a span of wire which can be engaged by hook member NJ on the arbor. Thus, as seen in Fig. 7, the wire, after having been pulled into one of these slits in the tube, forms, with the cut edges of a corner of the tube the side of a triangle. In the event that the tube be round, this section or span of wire would comprise the chord of an are which is formed by the out side of the tube. The proper width of slits l I will depend upon the diameter of the wire to be used. In any event, the slit should preferably be of such width that the edges thereof grip the wire slightly. These wire-gripping slits therefore obviate the need for any other means for initially anchoring the starting endof the wire, g

"If the winding tube, as shown in 1 Fig: 3;"is placed on the arbor of Fig. 2 so that the slits in the tube register with the entrance of slot 9;.th e.

wire will pass into the slot when it is pulleddown across the ends of the slit, as shown in Figs..5 and '7. More specifically, Fig. 5 shows the Wire] after it has been pulled down over the roller 4 (Fig. 1), passed under (or over) the arbor. and.

winding tube, and then pulled into the slits H, which, in the figure are facing the operators position. The slits will automatically register with the entrance openings in slots 9 when the winding.

tube 7 is pushed to the left on, arbor ,6 until ,it' strikes slide piece l2 which thus comprises astop.

Slide piece 12 is preferably arranged to slide axially along arbor 6 a distance depending upon the winding length 'of the coil to be wound. In

the construction illustrated in the drawings slide piece I2 is limited in its movement by, means of a countersunk set screw l3, the inside end of as illustrated in Figs. l and 5 for example, may

comprise a round piece of brass having a central opening which makes a good sliding fit on the arbor. Preferably it should be of ,such mass that the tube 1 may be slid quickly and with positive movement.

As above described, after the starting end portion of the wire i, Fig. 5, is passed behind (or. over) the arbor and is pressed into slot ll of the winding tube, leaving the terminal portion la of the wire protruding, a short length of the wire will span a portion of the inside of the tube and pass within the slot 9. Then, by sliding tube 1. to the right, as shown in Fig. 6, hook member Iii will engage that short span of wire, and will lengthen it by drawing a loop of wire lb inside of the tube. If the pull of the hook member is substantially even along each side of the loop, the length of wire drawn within the tube from the feed strand I and from the end portion la will be about equal. the purpose of sliding tube 1 axially along arbor 6 is to draw a length of wire within the tube, it

It will be evident thatsince ZAMAQZ s immaterial. whe her. th tube or. e. a bor. moved, a ons as mer ssuflici t e at v mm-v Inent between them. Furthermore, it is not essential that this relative motion be axial, because the respective parts may be designed for appropriate relative rotation. In any event, the rb r. shou d, e c n t cte s hat a s a i inthe tube is provided intowhich the wire loop be. drawn- Su space i lea shown in Fig. 7 on each side of hook member, l0.

Referring again to 6, after the loop. lb has-been drawn within the winding tube 1 it is desirable that the short end, la still protruding irom theslit l I be snipped ofi substantially flush w t t ex e Sur ac o he. dins ub The, winding operationcan then be commenced without further alignment or, anchoring of the starting end of the wire because, as above explained, the wires are automatically spaced and correctly, aligned with the guide grooves 5 of the roller 4 merely by pulling the starting end portions: of the wire into the slits. H of the winding tube, theedgcs of which firmly grip the wires. Furthermore, after each wire loop has been drawn within the tube, as, illustrated in Fig. 6, e a t se fifths. wi ear ec nchored because the wires two sharp. turns around the tube wall through the slits H and two more sharp turns. around the hook members [0. Consequently there is no possibility of the starting ends pulling loose when the winding operation, commences.

The winding of, the coil; may then proceed in theiusual manner until the required number of turns have been wound. A turns counter geared to the arbor. and positioned within sightv of the operator is customarily, provided so that she can seeat. alltimes the number of. turns of wire which have been applied, to the coils. In winding electric coils a sheet of insulating material, such as paper, is usually, inserted between the layers of wire, and. a final insulating or cover sheet (l5, Fig. 8) applied'before. the last turn of wire is wound, after which the winding machine is stopped anda strip of adhesive tape or paper l6 afiix'ed longitudinally of the coil so as tov secure the lapped ends of the cover sheet-together and at the same time toanchor the outside end 18 of the winding. It is convenient to employ an outside anchor strip on which are printed 53, series o f v s l9, asshown in Fig, 8, which point toward theflend oflthe coilnea'rest which the starting end lb is located. After the outside end is anchored; as 'just described, the right hand end of the arbor, as shown in the figures, may be swung out permitting the tube 1 carrying its windingsto be slipped off-the arbor. This step of sliding the tube off thearbor will cause the hook members It) to pull theiree ends of the startingportions of the wire wholly within the tube. As is customary in the artthe several coils wound alongtube I may then be cut apart by suitable. meanssuch as a small, high. speed circular. saw. The, resulting coils will have the appearance illustrated in Fig. 8 wherein the terminal endsofithe coilcomprising theinside and outside connecting leads lb and l8, respectively, are shown.

The method of winding one or more coils in accordance with the invention is more simple than previousmethods andinay be recapitulated as follows: First, a slitted winding tube, as shown in Fig. 3, is slipped over one end of the winding arbor 6 5,0 thatslits l'l cross the spline Scarrying'hook members '10, the" tube being pushed on until it is stopped by abutting against slide piece [2 in its extreme left-hand position. Second, assuming that the arbor rotates clockwise when viewed from the right-hand end in the figures as indicated by the arrows, the wires are passed through guide grooves 5 of roller 4, behind (or over) tube 1 and under and to the front (or rear) of the tube, and then manually pulled tightly into the slits ll, thus automatically locating and anchoring the starting ends of the windings and leaving a short free end of wire. Third, slide piece 12 is slid to the right as far as it will go, which operation moves the winding tube 1 axially on the arbor and automatically draws a loopof wire-within the tube for each coil. The operator then ships off the protruding free ends of'the wires flush with the outside surface of the tube. Fourth, the coils are Wound in as many layers, and insulated, as required,

' after which the outside of the coil is finished and the outside end of the wire is anchored in the usual manner Fifth, the winding tube.

carrying itscoils is slid off the arbor, which automatically frees the starting ends of the coils within the tube. Sixth, the coils are cut apart,

leaving the anchored connecting leads accessible without further operations.

This invention has been described above in connection with a particular embodiment thereof which has proved eminently successful in practice, but it will be evident that many modifications may be made. without departing from the invention, which in its various aspects is limited only by the appended claims.

I claim:

1. In a coil Winding machine, the combination which comprises, a rotatable arbor supported so that a winding tube may be slipped overone end thereof, an L-shaped slot cut in'the surface of said arbor to form a hook member, said slot being of depth sufiicient toreceive and said hook member being shaped to hold a section of the wire to be Wound, said slot being adapted to regis-. ter with a wirerreceiving slit in the wall of the winding tube, andmeansfor moving said tube a predetermined.distanceonsaid arbor so that said hook member draws a predetermined length of wire within said tube.

2. The combination according to claim 1 wherein said means for moving said tube comprises a slide piece abuttingone end of said tube and arranged toslide axially onsaid arbor, and stop means on said arboragainst which a portion of said slide piece strikesforlimiting the distance which said slidepiecemay move.

3. The combination; accordingv to claim 2 wherein said slide piece alsocomprises a stop member, proportioned so that when said winding tube abuts .thereagainst the slit in said tube automatically registers withtheslot in the surface of said arbor.

4, In a multiple-coil winding machine, the combination which comprises, a rotatable arbor supported so that a winding tube may be slipped over one end thereof, a plurality of slotscut in the surface of said arbor to form a similar number of hook members equally 'spaced along said arbor, each slot being of depth suflicient to receive a section of the wire to be wound, a plurality of wire guides for feeding wires to said tube, said guides being spaced apart by the same distances as said hook members and being movable longitudinally of and parallel to said arbor a distance equal to the length of the coils to be wound, the slots in said arbor being adapted to register with 7* a plurality of-wire-receiving slits in the wall oi said tube, sliding means for moving said tube a predetermined longitudinal distance on said arbor so that said hook members draw predetermined lengths of wire within said tube through said slits, respectively, and stop means limiting the distance said sliding means can move 'said tube along said arbor.

5. 'In a multiple-coil winding machine, the combination which comprises, a rotatable arbor :supported so that a winding tube may he slipped over one end thereof, a plurality of slots cut in the surface ofsaid arbor to form a similar number of hook members spaced along said arbor, each slot being of depth sufiicient to receive and hold a section of the wire to be wound into a coil, a plurality of wire guides for feeding wires to said tube, said guides being movable longitudinally of and parallel to said arbor a distance equal to the length of the coils to be wound, the slots in said arbor being adapted to register with a plurality of wire-receiving slits in the wall of said tube, sliding means for moving said tube a predetermined longitudinal distance on said arbor so that said hook members draw predetermined lengths of wire Within said tube through said slits, respectively, and stop means limiting the distance said sliding means can move said tube along said arbor.

6. A winding machine arbor of the type adapted to rotate a winding tube slid thereover, said arbor comprising a bar of generally square crosssection, portions of two adjacent sides being cut away to form therebetween a spline running longitudinally of said arbor, the top of said spline comprising one corner of said square, and

L-shaped slots cut into said spline at intervals along said spline to form hook members adapted to draw wire through perforations in the wall of the tube when said tube and arbor are moved relatively to each other.

'7. In a winding machine arbor of the type which rotates a winding tube placed thereon, said arbor comprising a bar of which a portion frictionally engages said tube to rotate the same, a plurality of hook members spaced along said arbor intermediate the" ends thereof and adapted simultaneously to draw a plurality of wires through perforations in and similarly spaced along the wall of the tube when said tube and arbor are moved relatively to each other.

8. In a winding machine arbor of the type which rotates a winding tube placed thereon, said arbor comprising a bar of which a portion engages said tube to rotate the same, a hook member positioned intermediate the ends of said arbor and adapted to draw wire through a perforation in the wall of the tube when said tube and arbor are moved relatively to each other.

9. In a winding machine arbor of the type which rotates a winding tube placed thereon, said 'arbor comprising a bar of which a portion engages said tube to rotate the same, hook members formed flush with the surface and spaced along said arbor and adapted to draw wires through perforations in the wall of the tube when said tube and arbor are moved relatively to each other.

10. In a winding machine arbor of the type which rotates a winding tube placed thereon, said arbor comprising a bar of which a portion frictionally engages said tube to rotate the s'ame, -.a hook member formed flush with the surface and positioned intermediate the ends of said ari-borand adapted to draw wire through a perfo a tion in'the'wall of the tube whn'said tube'and arbor are moved relatively to each other.

11. In a winding machine arbor of the type which rotates a Winding tube placed thereon, said arbor comprising a bar of which a portion frictionally engages said tube to rotate the same, hook members spaced along said arbor and adapted to draw wires through perforations in the wall of the tube when said tube and hook members are moved relatively to each other. 12. In a winding machine arbor of the type which rotates a winding tube placed thereon, said arbor comprising a bar of which a portion engages said tube to rotate the same, a hook member positioned intermediate the ends of said arbor and adapted to draw wire through a perforation in the wall of the tube when said tube' and hook member are moved relatively to each other.

13. Ina winding machine arbor of the type which rotates a winding tube placed thereon, said arbor comprising a bar of which a portion engages said tube to rotate the same, hook members formed flush with the surface and spaced along said arbor and adapted to draw wires through perforations in the wall of the tube when said tube and hook members are moved relatively to each other.

' .14. In a winding machine arbor of the type which rotates a winding tube placed thereon, said arbor comprising a bar of which a portion frictionally engages said tube to rotate the same, a hook member formed flush with the surface and positioned intermediate the ends of said arbor and adapted to draw wire through a perforation in the wall of the tube when said tube and hook member are moved relatively to each other.

15. In combination with a winding machine arbor of generally square cross-section, and havmg a plurality of hook members flush with the surface and spaced apart in a row longitudinally of said arbor, a winding tube of generally square cross-section proportioned to fit snugly on said arbor, slits being cut through the wall of said tube across a corner thereof and spaced apart distances corresponding to the spacing of said hook members.

16. In a coil-winding tube of generally square cross-section proportioned to fit snugly over a winding machine arbor of corresponding crosssection, a plurality of single straight cuts through the wall of said tube across a corner thereof and spaced apart to coincide with the beginning of a turn of each of a plurality of coils to be wound thereon, said cuts forming single slits having strand-gripping sides between which the starting ends of said coils may be drawn to theinterior of said tube and spaced away from the interior corner thereof, the width of each slit being less than the Width of the strand with which the coil is to be wound. 17. In a method of winding a coil of wire on a winding tube rotatable on an arbor, the steps which include, drawing a starting portion of the wire through an aperture in the wall of said tube so as to span an inside portion of said tube,,engaging the wire comprising said span, drawing the same into a loop within said tubeand leaving a short free end of wire extending outside said tube, cutting off said free end externally of said tube, winding the coil, and drawing said loop until the end of said wire is within said tube.

18. In a method of winding a coil of wire on awinding tube rotatable on an arbor, a portion of the wall of said tube being cut across with a single narrow slit, the steps which include, drawing a starting portion of the wire through said slit so as to span the slitted inside portion of said tube, and thereby frictionally anchoring said wire in said slit, engaging the wire comprising said span, drawing the same into a loop within said tube, winding the coil, engaging said loop, and drawing said loop until the end of said wire is within said tube.

19. In a method of winding a coil of wire on a winding tube rotatable on an arbor, the steps which include, drawing a starting portion of the wire through an aperture in the wall of said tube so as to span an inside portion of said tube, engaging the wire comprising said span, drawing the same into a loop within said tube and leaving a short free end of wire extending outside said tube, winding the coil, and drawing said loop until the free end of said wire is within said tube.

20. The method of starting the winding of a coil of wire on a winding tube rotatable on an arbor, said tube having a slit cut through the wall thereof substantially at right angles to the 10 longitudinal axis of the tube, said slit being narrower than the thickness of the wire, which includes the steps of drawing a starting length of wire through said slit so that a portion of the wire spans the ends of said slit within the tube, thus spacing said portion away from the wall of the tube and frictionally anchoring the wire in said slit, engaging the span portion of said wire, and drawing at least said span portion into a loop within said tube, the end portion of the wire remaining anchored in said slit.

WILLIAM CONSTANT GREF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 644,311 Anderson Feb. 27, 1900 1,855,814 Zindel Apr. 26, 1932 1,881,377 Keirspe Oct. 4, 1932 

